i don't think you're over-estimating the rightward pull in the liberal party so much as you're underestimating the centrist pull behind mulcair's leadership.

the liberals actually nationalized oil in the 70s. that's pretty left-wing. as we know, they've been drifting right since and have recently crossed over and become what is really a moderate conservative party. the current liberals are rather literally what one might call a "progressive conservative" party. voters are beginning to realize this, and the level that it will decimate them in the short or medium term will be determined by how strongly they hold to it before they switch back to a more populist rhetoric. despite the rightward shift over many decades, the truth on the ground remains that liberals are liberals and they don't want to vote for conservatives.

further, mulcair is not david lewis. by any metric, he's considerably to the right of pierre trudeau. this idea that the ndp is still a paragon of leftist virtue is just not reality. the truth is that there's really not a lot preventing the kind of collaboration you're speaking of - not because the liberals don't lean right, but because the ndp doesn't really lean left anymore. there's differences. there will always be differences. but the differences between the liberals and the ndp are probably lesser than the differences within either of these parties.

if the electorate polarizes and the liberals get out of this election with a small, left-leaning rump caucus led by people like stephane dion, they could actually end up to the left of the current ndp. we could see another rat pack pop up. and, they might end up pushing the ndp to keep their promises. it's for *that* reason that i'd prefer to see the alignment stabilize in a way that allows for three, distinct parties. thesis, anti-thesis, synthesis.

it's just maybe the case that time has caught up to the liberals in a hurry, and a role reversal of thesis and synthesis is what is in order.

rabble.ca/blogs/bloggers/djclimenhaga/2015/07/alberta-shows-why-there-will-be-no-ndp-liberal-entente-despite-n